Process of preparing phosphoric acid esters



r 7 2,830,069 7 I; Patented Apr- 1958 PREPARATION OF THEHYDROXY-PHOSPHATE 433mg Example 1.-In a 2 liter 4 necked flask fitted with a thermometer, stirrer, gas inlet bubbler, and condenser, PROCESS F PREPARING PHOSPHORIC were placed 200 g. 1.73 m.) of 85%. H PO and 65 g. ACID ESTERS 5 (0.46 m. of P 0 Ethylene oxidewas bubbled intothe Paul V. Smith, In, Westfield, N. J.', assignor to'E brk mixture with stirring, at such a rate that'the temperature search and Engineering Company, a corporation of s was maintained at 50-60 C., until'a gain in Weight of Delaware 1100 g. was observed. A diluent, such as dioxaneymay beadded if desired. After stripping to constant weight No i fi g g gggi 1953 on-a steam bath, 1315 g. of product was obtainedu Acid, en 0.000 centiequivalent/g., alcohol, 0.608centiequivalent/g. 3 Claims; '(Cl. 260-461) 1 Example 2.In a 1 liter flask fitted with an esterificapositions which have unusual andspecific properties,

tion water trap and condenser were placed 100 g. (0.63 m.) C Oxo acid, 98 g. (0.6 equiv.) of the hydroxy phos phate, 100 ml. toluene, and 0.5 g. of p-toluene sulfonic lubricants having outstanding properties of viscosity at iggli g? g i i i ggg low and high temperatures. More particularly the invensolutibnz um neutral a dr'ying it ,Strippea to tion relates to new and --improved synthetic lubricants 202a/2Vmm which are formed by esterifying the reaction product of an alkylene oxide and phosphoric acid with a long chain aliphatic carboxylic acid.

In recent eflorts to obtain superior lubricating com- This invention relates to synthetic lubricating composi- 15 tions and particularly to new' and irnproved synthetic Example '3.--In a 1' liter fiaskfilled with a reflux condenser connected to a drying tubewere-pla'ced' 143 g. (0.64 m.) of a C Oxo acid chlorideiand 98 g? (0.6 equiv.) of hydroxy-phosphate. The mixture was refluxed there have been developed entirely new synthetic ma- 3:2 g i gggi fifl g 1233 2 :5222 ggfggifgfi f terials with lubricating properties. In general these new L 1 -The-materials prepared according to the inventive-consynthetic lubricants are characterized by vlscoslty properceptlwere submitted to the Standard ASTMYdeterminaties that are outstanding at both low and .high "temperations for flash point, pour point, and 'viscosity. at both tures, especially when compared to mineral-o ls. These 0 R and F Their ASTM slopes Vera-calculated outstandmg low and hlgh temperature Propel-hes tare as were. their viscosity indices: Data are presented in 'pecially desirable for use in equipment designed to opera Table I below ate over a great temperature differential, such as jet e'n gines or turbines'for aircraft use, internal combustion re- Table I ciprocating engine'sfor aircraft and the like. It has been w I foundthat mineral lubricating oils have generallyiundemEste-r v 53g; rslop V I sirable limitations forthelubricationof these:engines 1 -Acid" Value I W. *F. As'rly'r particularly in respect to their :high and low temperature I viscosity characteristics. It has also been found that'synthetic lubricants-may g :32 138 21%}; 8: be desirable for'the lubrication of'stan'dard automotive engines.- In addition to 'the'versatility'of'their' visco'sitybustion chamber deposit formation, particularly when 45. they are used for long periods of times Low rates of I These lubricants may also serve to-reduce or---remoye taining' such'deposits.

- of 'hydroxyphosphoric acid having the foll owing geneljal, I."

The above 'va'lu'es indicate that-the new synthetic lubritempeliature.relanonshlps some types .of'syrithetlczlubri' cents of "invention have outstanding properties oflow cants mvestlgated have another advantage in that-their ,poufpdinfafidrhighfias-h point; Their ASTM slopes and use has been found to result in very low'rates of comviscosity indie-2'5 Show that thes; have eiceuehtvisqsity temperature properties and therefore have outstanding "utili as 'lubricantsfor both low'and hi rtemoerature formation of combustion chamber deposits result in a V more eflicient utilization of fuel, less increase in the Tt'yform..th.hydmxy.compounds used as asmrfin, Octane re'qmremen-t f: an p leis'QPreilgmmn i material-'for'th'e prep'aration of the estersof this inven ency, and an'overall: mprovement in engine operation. tion. phosphoric 'acid be Teac-tedflwith, a number of alkylene oxides, The number. of units reacted .withone molecule of' the" acidmayb'e varied within wide ranges. s ""Foi" instance; insteadof"thefethylene'oxideiunitsfutilized h preisent. m m Relates a new.type of above;one"may"use'pronylene, butylene o xides, or mixthetlc lubricating composition-which comprises the esters mres Ofe-pdXides; Theln'umberof ufiitsrdaefiwm vary fdepeiiding" upon-the desired'i-no'lecular weight the combustion chamber deposit'sfrom aliiengine already conformula: product as well as the acid to be used to form the esters. It is preferred to use either ethylene oxide or propylene a oxide, however, and to add from about 3 to about l'Z units to each molecule of phosphoric acid. wherein R is a monovalent hydrocarbon radical, R is a As was pointed out above, the hydroxy-phesphate re divalent hydrocarbon radical, and I1 is a Ill-11111361" from sulting from the reaction of alkylene oxide to phosphoric 1 to 10. acid will have the formula:

The esters of this invention are prepared by reacting O a monocarboxylic aliphatic acid having from 6 to 20 11 carbon atoms per molecule with the reaction product of HO (R'O)FP (OR')"OH an alkylene oxide and phosphoric acid. (0R').0H

The invention will be more clearlyexplained by referwhere x y and 2 may be the Same or different integers @1166 0 the fOlIOWlHg eXamples, Whlch are to be 6011' It may be desirable to react three, two or one moles sidered as being illustrative only, and are not restrictive of acid with this hydroxy-phosphoric acid, and any numin scope. her up to and including three moles of acid may be used,

- 3 1 depending again upon the properties desired in the finished ester. It may also be desired to add different acids, or use a mixture of acids which may also be done. The acid used will ordinarily be a monocarboxylic acid having from about 6 to 20 carbonatoms per molecule and may be of either branched or straight chain configuration.

Especially preferred, and contemplated in the preferred embodiment of this invention are the highly branched chain acids that are derived from aldehydes or alcohols obtained by subjecting an olefin to the action of carbon monoxide and hydrogen in the Oxo process. This process, described in detail in U. S. Patent No. 2,367,066, issued to Roelen in 1943, involves the use of temperatures in the order of 150 C. to 350 C. and pressures of about 3000 pounds persquare inch, or higher.- A cobalt catalyst is used. When hydrogen is used in conjunction with the carbon monoxide an aldehyde results which may be converted to the acid by oxidation. Further hydrogenation of the aldehyde results in the alcohol which may be converted to the acid by caustic fusion, or other of the well known processes. If water is used instead of hydrogen, the acid results directly from the Oxo process. Preferred olefins are the polymers or copolymers .of C, and/or C olefins, the resulting polymer and copolymers with other polymerizable materials, such as copolymers of fumarate or maleate esters with vinyl or copolymer having from about 7 to about 16 carbon I atoms.

By using as a starting material the reaction product of the alkylene oxide and the phosphoric acid, that is, the hydroxyphosphates and other materials suchas dibasic acids and alcohols, one may build complex molecules which have varying properties. prepared has the following schematic formula:

Aleohol-dibasic acid hydroxy-phosphate-dtbasle acid-alcohol ibasic acid aleohol The, new synthetic lubricants of invention may be thickened to grease compositions by using any of the com-,

mon grease forming soaps. The alkali or'alkaline earth metal soaps of high molecular weight substantially saturated fatty acids may be used and the grease compositions prepared by any of the methods withwhich the art is familiar. ,For instance, such soaps as the oleates, stearates, hydroxy stearates, or ricinoleates of sodium, potassium, lithium, calcium, barium, strontium, aluminum, and the like may be used, as well as the soaps formed by heating animal, fish, or vegetable oils, with soda, lime, baria hydrate or lithia hydrate.

If it is desired to enhance particular properties of the synthetic lubricants of invention, they may be blended with additive agents, such as viscosity index improvers, pour point depressants, detergent inhibitors, oxidation inhibitors, and the like. Such materials as ester polymers acetate, acrylate or methacrylate polymers or copolymers, phenyl alpha naphthylamine, phenothiazine, 2,6-di-tert.- butyl-para-cresol and many other additive materials may be blended with the synthetic lubricants of this invention.

The esters of invention may also find wide application in a great variety of industrial uses outside the lubricant field. For instance, these new esters may have utility as plasticizers, solubilizers, heat transfer agents, insecticides, weed killers, r-ust'preventatives,.solvents, dewaxing aids, detergents, oiliness agents as in penetrating oils, and as raw materials for many other industrial applications. They may be blended with mineral oils, with other synthetic lubricants such as formals, dibasic acid esters, complex esters, polymerized hydrocarbons, and the like.

To reiterate briefly, the instant invention relates to new and improved synthetic lubricants which comprise a material of the formula wherein R is an alkyl group containing from 5 to 19 carbon atoms, wherein R represents a divalent hydrocarbon radical containing from 2 to 4 carbon atoms, and

' wherein x, y, and z are integers of from 1 to 10. R may One complex ester so i be alike or ditferent and is preferably branched chain in configuration.

What is claimed is:

l. A process for preparing an ester of the formula wherein R is a monovalent hydrocarbon radical, R is a divalent hydrocarbon radical of fromZ to 4 carbon atoms and his an integer of from 1 to 10, which com- 3. A process according to claim 1 wherein said alkylene oxide is ethylene oxide and said acid is a C Oxo acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,224,360 Rozenbrocket al. Dec. 3, 1 940 2,365,291 Prutton et a1. Dec. 14, 1944 2,643,261 Matuszak June 23, 1953 FOREIGN PATENTS 452,508 Great Britain Aug. 24, 1936 

1. A PROCESS FOR PREPARING AN ESTER OF THE FORMULA 